Kusangalatsa kwa ma harmonics achiwiri mumitundu yambiri

Kusangalatsa kwa ma harmonics achiwiri mumitundu yambiri

Chiyambireni kupezeka kwa mawonekedwe achiwiri osagwirizana ndi mawonekedwe a 1960s, kwadzutsa chidwi chachikulu cha ofufuza, mpaka pano, kutengera mawonekedwe achiwiri a harmonic, ndi pafupipafupi, apanga kuchokera ku ultraviolet kwambiri mpaka gulu lakutali la infrared.lasersimathandizira kwambiri kukula kwa laser,kuwalakukonza zidziwitso, kujambula kwapang'onopang'ono kwapamwamba kwambiri ndi magawo ena. Malinga ndi nonlinearopticsndi chiphunzitso cha polarization, mawonekedwe owoneka bwino osasinthika amalumikizana kwambiri ndi ma crystal symmetry, ndipo coefficient yosagwirizana ndi zero sizomwe zimangokhala pakatikati pa inversion symmetric media. Monga chofunikira kwambiri chachiwiri chopanda mzere, ma harmonics achiwiri amalepheretsa kwambiri mbadwo wawo komanso kugwiritsa ntchito bwino mu ulusi wa quartz chifukwa cha mawonekedwe aamorphous ndi symmetry of center inversion. Pakali pano, njira polarization (optical polarization, matenthedwe polarization, electric field polarization) akhoza artificially kuwononga symmetry wa zinthu pakati inversion wa CHIKWANGWANI kuwala, ndi bwino kusintha wachiwiri kuti nonlinearity ulusi kuwala. Komabe, njirayi imafuna ukadaulo wokonzekeretsa wovuta komanso wovuta, ndipo ukhoza kungokwaniritsa magawo ofananirako pamlingo wa discrete wavelengths. Mphete ya kuwala kwa fiber resonant yotengera echo wall mode imachepetsa chisangalalo chambiri cha ma harmonics achiwiri. Pothyola symmetry ya mawonekedwe apamwamba a fiber, ma harmonics apamwamba achiwiri mumtundu wapadera wa fiber amawonjezedwa kumlingo wina, komabe amadalira pampu ya femtosecond ndi mphamvu yapamwamba kwambiri. Chifukwa chake, m'badwo wachiwiri wachiwiri wopanda mawonekedwe owoneka bwino m'mapangidwe onse a ulusi komanso kusinthika kwa magwiridwe antchito, makamaka m'badwo wa ma harmonics achiwiri omwe ali ndi mphamvu zochepa, kupopera kosalekeza kopitilira muyeso, ndizovuta zomwe ziyenera kuthetsedwa m'munda wa fiber optics ndi zida zopanda mzere, komanso kukhala ndi tanthauzo lofunikira la sayansi komanso kufunika kogwiritsa ntchito.

Gulu lofufuza ku China lakonza dongosolo lophatikizira gallium selenide crystal phase ndi micro-nano fiber. Pogwiritsa ntchito mwayi wapamwamba wachiwiri wosasinthika komanso kuyitanitsa kwautali kwa makristasi a gallium selenide, kusangalatsa kwachiwiri kwa harmonic komanso kusinthika kwapang'onopang'ono kumakwaniritsidwa, kumapereka njira yatsopano yopititsira patsogolo njira zama parametric mu fiber ndikukonzekera Broadband yachiwiri-harmonic.magwero a kuwala. Kusangalatsa kwamphamvu kwachiwiri kwa harmonic ndi kuchuluka kwafupipafupi mu chiwembu kumatengera zinthu zitatu zotsatirazi: mtunda wautali wolumikizana pakati pa gallium selenide ndi gallium selenide.micronano fiber, dongosolo lachiwiri lachiwiri losagwirizana ndi dongosolo lautali la gallium selenide crystal yosanjikiza, ndipo magawo ofananirako a ma frequency ofunikira komanso kuwirikiza kawiri amakhutitsidwa.

Pakuyesako, ulusi wa micro-nano wokonzedwa ndi makina owunikira moto uli ndi gawo lofananira la cone mu dongosolo la millimeter, lomwe limapereka utali wotalikirapo wotalikirapo pakuwunikira kwapampu ndi funde lachiwiri la harmonic. Polarizability yachiwiri yopanda malire ya kristalo ya gallium selenide yophatikizika imaposa 170 pm / V, yomwe ndi yapamwamba kwambiri kuposa polarizability yamkati yopanda mawonekedwe a fiber optical. Komanso, mawonekedwe aatali a gallium selenide crystal amatsimikizira kusokonezeka kwa gawo lachiwiri la ma harmonics, kupereka masewera athunthu kuti apindule ndi kutalika kwakukulu kosasunthika mu micro-nano fiber. Chofunika kwambiri, gawo lofananira pakati pa kupopera optical base mode (HE11) ndi yachiwiri ya harmonic high order mode (EH11, HE31) imazindikirika poyang'anira kukula kwa cone ndikuwongolera kufalikira kwa ma waveguide panthawi yokonzekera micro-nano fiber.

Zomwe zili pamwambazi zimayala maziko osangalatsa komanso otambalala a ma harmonics achiwiri mu micro-nano fiber. Kuyesera kumasonyeza kuti linanena bungwe lachiwiri harmonics pa mlingo nanowatt chingapezeke pansi pa 1550 nm picosecond zimachitika laser mpope, ndi harmonics wachiwiri akhoza kukhala okondwa efficiently pansi pa mpope mosalekeza laser wa wavelength yemweyo, ndi mphamvu pakhomo ndi otsika ngati mazana angapo microwatts (Chithunzi 1). Kupitilira apo, kuwala kwa pampu kumakulitsidwa mpaka mafunde atatu osiyanasiyana a laser mosalekeza (1270/1550/1590 nm), ma harmonics atatu achiwiri (2w1, 2w2, 2w3) ndi ma siginecha atatu afupipafupi (w1 + w2, w1 + w3, w2 + w3) amawonedwa pagawo lililonse la ma frequency asanu ndi limodzi. Mwa kusintha kuwala kwa mpope ndi gwero lowala kwambiri la kuwala kotulutsa diode (SLED) ndi bandwidth ya 79.3 nm, harmonic yachiwiri yachiwiri yokhala ndi 28.3 nm imapangidwa (Chithunzi 2). Kuphatikiza apo, ngati ukadaulo woyika mpweya wamankhwala ukhoza kugwiritsidwa ntchito m'malo mwaukadaulo wosinthira wowuma mu phunziroli, ndipo magawo ochepa a makristalo a gallium selenide amatha kukulitsidwa pamwamba pa micro-nano fiber pamtunda wautali, kusinthika kwachiwiri kwa harmonic kukuyembekezeka kupititsidwa patsogolo.

CHITH. 1 Dongosolo lachiwiri la Harmonic Generation ndipo limabweretsa mawonekedwe amtundu wonse

Chithunzi 2 Kusanganikirana kwa mafunde ambiri ndi ma harmonics achiwiri otalikirapo pansi pa kupopera kosalekeza